1. Field of the Invention
The instant invention relates generally to the field of dust collectors of the back pulsed self-cleaning type. More specifically, it describes a mechanism/system, preferably biased, for releasably locking and supporting the filters utilized in such dust collectors in their operative position.
2. Prior Art in the Field
Most back pulsed dust collectors in current usage are similar in general operation to, and a good example of same may be found in, the system disclosed in U.S. Pat. No. 4,218,227. These systems are, in turn, quite similar in operation to the bag house filter assemblies that were known and used many years before the development of the more efficient and portable dust collectors in current usage.
Dust collectors of the back pulsed self-cleaning variety are generally comprised of a large housing which is partitioned into two sections: a "dirty" section and a "clean" section. Typically, the "clean" section is located above the "dirty" section in the housing. Dust laden air to be filtered enters the lower ("dirty") section and, under pressure, is forced through a series of dust filters mounted on or in the partition (which serve to remove substantially all of the dust from the air) into the upper ("clean") section. From this point the dust free air exits the housing and can be exhausted or used for a variety of purposes.
The filter elements that are almost universally utilized for the purpose of filtering dust from the air passing through such devices are of the cylindrical pleated paper variety having a mounting plate at their open end. Generally, such filters are removably mounted in one or more rows within the lower section of the dust collector housing. The open upper end of the filter elements must be tightly butted against the partition between the two sections when mounted so that the gasket provided on the mounting plate forms an air tight seal therewith. Circular apertures are provided in the partition in axial alignment with the open end of the secured filter elements such that the interior of the filter elements is in communication with the upper "clean" air section of the housing. Air passes through the filter (leaving entrained dust on the exterior thereof) and enters the interior of the cylindrical filter element. From there it is forced by the pressure differential between the upper section and the lower section into the upper section where, as previously noted, it exits the housing.
As dust continues to accumulate on the exterior of the filter elements, it is necessary to periodically clean the elements by back pulsing a jet of air downwardly through the interior of the filter element. This creates a temporary increase in air pressure within the filter in excess of the pressure outside of same, forcing dust particles away from its surface. Once released from the surface of the filter, such particles will (in general) fall to the bottom of the lower section where an auger or some other means can be utilized to remove them from the housing. Back pulsing can extend the useful life of the filter elements and help to prevent them from becoming overly laden with dust. However, at some point it is necessary to remove such filter elements for replacement. Without some means of easily and efficiently removing such elements, this can be a time consuming and dirty task for the operator. Further, since the dust accumulated on such filters may have toxic or other harmful properties, these drawbacks of removal are more than a mere inconvenience. A quick, clean and efficient means for mounting and removing dust filters is, therefore, a necessity for safe and efficient operation.
Numerous attempts to develop systems for efficiently mounting dust filters so as to be quickly and easily removable have been made in the past. These attempts have met with only limited success. Examples of such prior art devices/systems may be found in the following patents:
(1) U.S. Pat. No. 3,131,044 issued to W. E. Springer in 1964 for a Filter Bag and Suspension For Dust Collecting Apparatus. PA1 (2) U.S. Pat. No. 3,668,843 issued to Westlin et al. in 1972 for a Filter Support Construction. PA1 (3) U.S. Pat. No. 4,322,231 issued to Hilzendeger et al. in 1982 for a Filter Element Locking Mechanism. PA1 (4) U.S. Pat. No. 4,323,376 issued to Rosenquist in 1982 for a Dust Collector With Quick Release Filter Support System for Use in Dust Collectors. PA1 (5) U.S. Pat. No. 5,123,944 issued to Cooper in 1992 for Removable Filter Units.
However, none of said attempts in any way foreshadow, anticipate or render obvious the novel and creative advances and teachings of this invention.